fix(inputs.http_response): Fix for IPv4 and IPv6 addresses when interface is set (#15496)

docs/LICENSE_OF_DEPENDENCIES.md

@@ -323,6 +323,8 @@ following works:
 - github.com/russross/blackfriday [BSD 2-Clause "Simplified" License](https://github.com/russross/blackfriday/blob/master/LICENSE.txt)
 - github.com/safchain/ethtool [Apache License 2.0](https://github.com/safchain/ethtool/blob/master/LICENSE)
 - github.com/samber/lo [MIT License](https://github.com/samber/lo/blob/master/LICENSE)
+- github.com/seancfoley/bintree [Apache License 2.0](https://github.com/seancfoley/bintree/blob/master/LICENSE)
+- github.com/seancfoley/ipaddress-go [Apache License 2.0](https://github.com/seancfoley/ipaddress-go/blob/master/LICENSE)
 - github.com/shirou/gopsutil [BSD 3-Clause Clear License](https://github.com/shirou/gopsutil/blob/master/LICENSE)
 - github.com/shoenig/go-m1cpu [Mozilla Public License 2.0](https://github.com/shoenig/go-m1cpu/blob/main/LICENSE)
 - github.com/shopspring/decimal [MIT License](https://github.com/shopspring/decimal/blob/master/LICENSE)

go.mod

@@ -169,6 +169,7 @@ require (
 	github.com/robinson/gos7 v0.0.0-20240315073918-1f14519e4846
 	github.com/safchain/ethtool v0.3.0
 	github.com/santhosh-tekuri/jsonschema/v5 v5.3.1
+	github.com/seancfoley/ipaddress-go v1.6.0
 	github.com/sensu/sensu-go/api/core/v2 v2.16.0
 	github.com/shirou/gopsutil/v3 v3.24.4
 	github.com/showwin/speedtest-go v1.7.7
@@ -437,6 +438,7 @@ require (
 	github.com/robfig/cron/v3 v3.0.1 // indirect
 	github.com/russross/blackfriday/v2 v2.1.0 // indirect
 	github.com/samber/lo v1.38.1 // indirect
+	github.com/seancfoley/bintree v1.3.1 // indirect
 	github.com/shoenig/go-m1cpu v0.1.6 // indirect
 	github.com/shopspring/decimal v1.3.1 // indirect
 	github.com/signalfx/com_signalfx_metrics_protobuf v0.0.3 // indirect

go.sum

@@ -2113,6 +2113,10 @@ github.com/scaleway/scaleway-sdk-go v1.0.0-beta.21 h1:yWfiTPwYxB0l5fGMhl/G+liULu
 github.com/scaleway/scaleway-sdk-go v1.0.0-beta.21/go.mod h1:fCa7OJZ/9DRTnOKmxvT6pn+LPWUptQAmHF/SBJUGEcg=
 github.com/sean-/seed v0.0.0-20170313163322-e2103e2c3529 h1:nn5Wsu0esKSJiIVhscUtVbo7ada43DJhG55ua/hjS5I=
 github.com/sean-/seed v0.0.0-20170313163322-e2103e2c3529/go.mod h1:DxrIzT+xaE7yg65j358z/aeFdxmN0P9QXhEzd20vsDc=
+github.com/seancfoley/bintree v1.3.1 h1:cqmmQK7Jm4aw8gna0bP+huu5leVOgHGSJBEpUx3EXGI=
+github.com/seancfoley/bintree v1.3.1/go.mod h1:hIUabL8OFYyFVTQ6azeajbopogQc2l5C/hiXMcemWNU=
+github.com/seancfoley/ipaddress-go v1.6.0 h1:9z7yGmOnV4P2ML/dlR/kCJiv5tp8iHOOetJvxJh/R5w=
+github.com/seancfoley/ipaddress-go v1.6.0/go.mod h1:TQRZgv+9jdvzHmKoPGBMxyiaVmoI0rYpfEk8Q/sL/Iw=
 github.com/sensu/sensu-go/api/core/v2 v2.16.0 h1:HOq4rFkQ1S5ZjxmMTLc5J5mAbECrnKWvtXXbMqr3j9s=
 github.com/sensu/sensu-go/api/core/v2 v2.16.0/go.mod h1:MjM7+MCGEyTAgaZ589SiGHwYiaYF7N/58dU0J070u/0=
 github.com/sergi/go-diff v1.0.0/go.mod h1:0CfEIISq7TuYL3j771MWULgwwjU+GofnZX9QAmXWZgo=

plugins/inputs/http_response/http_response.go

@@ -17,6 +17,8 @@ import (
 	"unicode/utf8"
 
 	"github.com/benbjohnson/clock"
+	"github.com/seancfoley/ipaddress-go/ipaddr"
+
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/config"
 	"github.com/influxdata/telegraf/internal"
@@ -36,40 +38,45 @@ const (
 
 // HTTPResponse struct
 type HTTPResponse struct {
-	Address         string   `toml:"address" deprecated:"1.12.0;1.35.0;use 'urls' instead"`
+	Address         string              `toml:"address" deprecated:"1.12.0;1.35.0;use 'urls' instead"`
-	URLs            []string `toml:"urls"`
+	URLs            []string            `toml:"urls"`
-	HTTPProxy       string   `toml:"http_proxy"`
+	HTTPProxy       string              `toml:"http_proxy"`
-	Body            string
+	Body            string              `toml:"body"`
 	BodyForm        map[string][]string `toml:"body_form"`
-	Method          string
+	Method          string              `toml:"method"`
-	ResponseTimeout config.Duration
+	ResponseTimeout config.Duration     `toml:"response_timeout"`
-	HTTPHeaderTags  map[string]string `toml:"http_header_tags"`
+	HTTPHeaderTags  map[string]string   `toml:"http_header_tags"`
-	Headers         map[string]string
+	Headers         map[string]string   `toml:"headers"`
-	FollowRedirects bool
+	FollowRedirects bool                `toml:"follow_redirects"`
 	// Absolute path to file with Bearer token
 	BearerToken         string      `toml:"bearer_token"`
 	ResponseBodyField   string      `toml:"response_body_field"`
 	ResponseBodyMaxSize config.Size `toml:"response_body_max_size"`
-	ResponseStringMatch string
+	ResponseStringMatch string      `toml:"response_string_match"`
-	ResponseStatusCode  int
+	ResponseStatusCode  int         `toml:"response_status_code"`
-	Interface           string
+	Interface           string      `toml:"interface"`
 	// HTTP Basic Auth Credentials
 	Username config.Secret `toml:"username"`
 	Password config.Secret `toml:"password"`
 	tls.ClientConfig
 	cookie.CookieAuthConfig
 
-	Log telegraf.Logger
+	Log telegraf.Logger `toml:"-"`
 
 	compiledStringMatch *regexp.Regexp
-	client              httpClient
+	clients             []client
+}
+
+type client struct {
+	httpClient httpClient
+	address    string
 }
 
 type httpClient interface {
 	Do(req *http.Request) (*http.Response, error)
 }
 
-// Set the proxy. A configured proxy overwrites the system wide proxy.
+// Set the proxy. A configured proxy overwrites the system-wide proxy.
 func getProxyFunc(httpProxy string) func(*http.Request) (*url.URL, error) {
 	if httpProxy == "" {
 		return http.ProxyFromEnvironment
@@ -85,9 +92,9 @@ func getProxyFunc(httpProxy string) func(*http.Request) (*url.URL, error) {
 	}
 }
 
-// createHTTPClient creates an http client which will timeout at the specified
+// createHTTPClient creates an http client which will time out at the specified
 // timeout period and can follow redirects if specified
-func (h *HTTPResponse) createHTTPClient() (*http.Client, error) {
+func (h *HTTPResponse) createHTTPClient(address url.URL) (*http.Client, error) {
 	tlsCfg, err := h.ClientConfig.TLSConfig()
 	if err != nil {
 		return nil, err
@@ -96,7 +103,7 @@ func (h *HTTPResponse) createHTTPClient() (*http.Client, error) {
 	dialer := &net.Dialer{}
 
 	if h.Interface != "" {
-		dialer.LocalAddr, err = localAddress(h.Interface)
+		dialer.LocalAddr, err = localAddress(h.Interface, address)
 		if err != nil {
 			return nil, err
 		}
@@ -127,7 +134,7 @@ func (h *HTTPResponse) createHTTPClient() (*http.Client, error) {
 	return client, nil
 }
 
-func localAddress(interfaceName string) (net.Addr, error) {
+func localAddress(interfaceName string, address url.URL) (net.Addr, error) {
 	i, err := net.InterfaceByName(interfaceName)
 	if err != nil {
 		return nil, err
@@ -138,14 +145,43 @@ func localAddress(interfaceName string) (net.Addr, error) {
 		return nil, err
 	}
 
+	urlInIPv6, zone := isURLInIPv6(address)
 	for _, addr := range addrs {
 		if naddr, ok := addr.(*net.IPNet); ok {
-			// leaving port set to zero to let kernel pick
+			ipNetInIPv6 := isIPNetInIPv6(naddr)
-			return &net.TCPAddr{IP: naddr.IP}, nil
+
+			// choose interface address in the same format as server address
+			if ipNetInIPv6 == urlInIPv6 {
+				// leaving port set to zero to let kernel pick, but set zone
+				return &net.TCPAddr{IP: naddr.IP, Zone: zone}, nil
+			}
 		}
 	}
 
-	return nil, fmt.Errorf("cannot create local address for interface %q", interfaceName)
+	return nil, fmt.Errorf("cannot create local address for interface %q and server address %q", interfaceName, address.String())
+}
+
+// isURLInIPv6 returns (true, zoneName) only when URL is in IPv6 format.
+// For other cases (host part of url cannot be successfully validated, doesn't contain address at all or is in IPv4 format), it returns (false, "").
+func isURLInIPv6(address url.URL) (bool, string) {
+	host := ipaddr.NewHostName(address.Host)
+	if err := host.Validate(); err != nil {
+		return false, ""
+	}
+	if hostAddr := host.AsAddress(); hostAddr != nil {
+		if ipv6 := hostAddr.ToIPv6(); ipv6 != nil {
+			return true, ipv6.GetZone().String()
+		}
+	}
+
+	return false, ""
+}
+
+// isIPNetInIPv6 returns true only when IPNet can be represented in IPv6 format.
+// For other cases (address cannot be successfully parsed or is in IPv4 format), it returns false.
+func isIPNetInIPv6(address *net.IPNet) bool {
+	ipAddr, err := ipaddr.NewIPAddressFromNetIPNet(address)
+	return err == nil && ipAddr.ToIPv6() != nil
 }
 
 func setResult(resultString string, fields map[string]interface{}, tags map[string]string) {
@@ -196,10 +232,10 @@ func setError(err error, fields map[string]interface{}, tags map[string]string)
 }
 
 // HTTPGather gathers all fields and returns any errors it encounters
-func (h *HTTPResponse) httpGather(u string) (map[string]interface{}, map[string]string, error) {
+func (h *HTTPResponse) httpGather(cl client) (map[string]interface{}, map[string]string, error) {
 	// Prepare fields and tags
 	fields := make(map[string]interface{})
-	tags := map[string]string{"server": u, "method": h.Method}
+	tags := map[string]string{"server": cl.address, "method": h.Method}
 
 	var body io.Reader
 	if h.Body != "" {
@@ -214,7 +250,7 @@ func (h *HTTPResponse) httpGather(u string) (map[string]interface{}, map[string]
 		body = strings.NewReader(values.Encode())
 	}
 
-	request, err := http.NewRequest(h.Method, u, body)
+	request, err := http.NewRequest(h.Method, cl.address, body)
 	if err != nil {
 		return nil, nil, err
 	}
@@ -245,14 +281,14 @@ func (h *HTTPResponse) httpGather(u string) (map[string]interface{}, map[string]
 
 	// Start Timer
 	start := time.Now()
-	resp, err := h.client.Do(request)
+	resp, err := cl.httpClient.Do(request)
 	responseTime := time.Since(start).Seconds()
 
 	// If an error in returned, it means we are dealing with a network error, as
 	// HTTP error codes do not generate errors in the net/http library
 	if err != nil {
 		// Log error
-		h.Log.Debugf("Network error while polling %s: %s", u, err.Error())
+		h.Log.Debugf("Network error while polling %s: %s", cl.address, err.Error())
 
 		// Get error details
 		if setError(err, fields, tags) == nil {
@@ -352,10 +388,9 @@ func (*HTTPResponse) SampleConfig() string {
 	return sampleConfig
 }
 
-// Gather gets all metric fields and tags and returns any errors it encounters
+func (h *HTTPResponse) Init() error {
-func (h *HTTPResponse) Gather(acc telegraf.Accumulator) error {
+	// Compile the body regex if it exists
-	// Compile the body regex if it exist
+	if h.ResponseStringMatch != "" {
-	if h.compiledStringMatch == nil {
 		var err error
 		h.compiledStringMatch, err = regexp.Compile(h.ResponseStringMatch)
 		if err != nil {
@@ -367,7 +402,6 @@ func (h *HTTPResponse) Gather(acc telegraf.Accumulator) error {
 	if h.ResponseTimeout < config.Duration(time.Second) {
 		h.ResponseTimeout = config.Duration(time.Second * 5)
 	}
-	// Check send and expected string
 	if h.Method == "" {
 		h.Method = "GET"
 	}
@@ -380,32 +414,37 @@ func (h *HTTPResponse) Gather(acc telegraf.Accumulator) error {
 		}
 	}
 
-	if h.client == nil {
+	h.clients = make([]client, 0, len(h.URLs))
-		client, err := h.createHTTPClient()
-		if err != nil {
-			return err
-		}
-		h.client = client
-	}
-
 	for _, u := range h.URLs {
 		addr, err := url.Parse(u)
 		if err != nil {
-			acc.AddError(err)
+			return fmt.Errorf("%q is not a valid address: %w", u, err)
-			continue
 		}
 
 		if addr.Scheme != "http" && addr.Scheme != "https" {
-			acc.AddError(errors.New("only http and https are supported"))
+			return fmt.Errorf("%q is not a valid address: only http and https types are supported", u)
-			continue
 		}
 
+		cl, err := h.createHTTPClient(*addr)
+		if err != nil {
+			return err
+		}
+
+		h.clients = append(h.clients, client{httpClient: cl, address: u})
+	}
+
+	return nil
+}
+
+// Gather gets all metric fields and tags and returns any errors it encounters
+func (h *HTTPResponse) Gather(acc telegraf.Accumulator) error {
+	for _, c := range h.clients {
 		// Prepare data
 		var fields map[string]interface{}
 		var tags map[string]string
 
 		// Gather data
-		fields, tags, err = h.httpGather(u)
+		fields, tags, err := h.httpGather(c)
 		if err != nil {
 			acc.AddError(err)
 			continue

plugins/inputs/http_response/http_response_test.go

@@ -1,7 +1,3 @@
-//go:build !windows
-
-// TODO: Windows - should be enabled for Windows when https://github.com/influxdata/telegraf/issues/8451 is fixed
-
 package http_response
 
 import (
@@ -200,9 +196,10 @@ func TestHeaders(t *testing.T) {
 			"Host":         "Hello",
 		},
 	}
+
 	var acc testutil.Accumulator
-	err := h.Gather(&acc)
+	require.NoError(t, h.Init())
-	require.NoError(t, err)
+	require.NoError(t, h.Gather(&acc))
 
 	expectedFields := map[string]interface{}{
 		"http_response_code": http.StatusOK,
@@ -239,8 +236,8 @@ func TestFields(t *testing.T) {
 	}
 
 	var acc testutil.Accumulator
-	err := h.Gather(&acc)
+	require.NoError(t, h.Init())
-	require.NoError(t, err)
+	require.NoError(t, h.Gather(&acc))
 
 	expectedFields := map[string]interface{}{
 		"http_response_code": http.StatusOK,
@@ -278,8 +275,8 @@ func TestResponseBodyField(t *testing.T) {
 	}
 
 	var acc testutil.Accumulator
-	err := h.Gather(&acc)
+	require.NoError(t, h.Init())
-	require.NoError(t, err)
+	require.NoError(t, h.Gather(&acc))
 
 	expectedFields := map[string]interface{}{
 		"http_response_code": http.StatusOK,
@@ -313,8 +310,8 @@ func TestResponseBodyField(t *testing.T) {
 	}
 
 	acc = testutil.Accumulator{}
-	err = h.Gather(&acc)
+	require.NoError(t, h.Init())
-	require.NoError(t, err)
+	require.NoError(t, h.Gather(&acc))
 
 	expectedFields = map[string]interface{}{
 		"result_type": "body_read_error",
@@ -349,6 +346,7 @@ func TestResponseBodyFormField(t *testing.T) {
 	}
 
 	var acc testutil.Accumulator
+	require.NoError(t, h.Init())
 	require.NoError(t, h.Gather(&acc))
 
 	expectedFields := map[string]interface{}{
@@ -387,8 +385,8 @@ func TestResponseBodyMaxSize(t *testing.T) {
 	}
 
 	var acc testutil.Accumulator
-	err := h.Gather(&acc)
+	require.NoError(t, h.Init())
-	require.NoError(t, err)
+	require.NoError(t, h.Gather(&acc))
 
 	expectedFields := map[string]interface{}{
 		"result_type": "body_read_error",
@@ -421,8 +419,8 @@ func TestHTTPHeaderTags(t *testing.T) {
 	}
 
 	var acc testutil.Accumulator
-	err := h.Gather(&acc)
+	require.NoError(t, h.Init())
-	require.NoError(t, err)
+	require.NoError(t, h.Gather(&acc))
 
 	expectedFields := map[string]interface{}{
 		"http_response_code": http.StatusOK,
@@ -456,8 +454,8 @@ func TestHTTPHeaderTags(t *testing.T) {
 	}
 
 	acc = testutil.Accumulator{}
-	err = h.Gather(&acc)
+	require.NoError(t, h.Init())
-	require.NoError(t, err)
+	require.NoError(t, h.Gather(&acc))
 
 	expectedTags = map[string]interface{}{
 		"server":      nil,
@@ -479,8 +477,8 @@ func TestHTTPHeaderTags(t *testing.T) {
 	}
 
 	acc = testutil.Accumulator{}
-	err = h.Gather(&acc)
+	require.NoError(t, h.Init())
-	require.NoError(t, err)
+	require.NoError(t, h.Gather(&acc))
 
 	expectedFields = map[string]interface{}{
 		"result_type": "connection_failed",
@@ -538,8 +536,8 @@ func TestInterface(t *testing.T) {
 	}
 
 	var acc testutil.Accumulator
-	err = h.Gather(&acc)
+	require.NoError(t, h.Init())
-	require.NoError(t, err)
+	require.NoError(t, h.Gather(&acc))
 
 	expectedFields := map[string]interface{}{
 		"http_response_code": http.StatusOK,
@@ -574,9 +572,10 @@ func TestRedirects(t *testing.T) {
 		},
 		FollowRedirects: true,
 	}
+
 	var acc testutil.Accumulator
-	err := h.Gather(&acc)
+	require.NoError(t, h.Init())
-	require.NoError(t, err)
+	require.NoError(t, h.Gather(&acc))
 
 	expectedFields := map[string]interface{}{
 		"http_response_code": http.StatusOK,
@@ -605,9 +604,10 @@ func TestRedirects(t *testing.T) {
 		},
 		FollowRedirects: true,
 	}
+
 	acc = testutil.Accumulator{}
-	err = h.Gather(&acc)
+	require.NoError(t, h.Init())
-	require.NoError(t, err)
+	require.NoError(t, h.Gather(&acc))
 
 	expectedFields = map[string]interface{}{
 		"result_type": "connection_failed",
@@ -642,9 +642,10 @@ func TestMethod(t *testing.T) {
 		},
 		FollowRedirects: true,
 	}
+
 	var acc testutil.Accumulator
-	err := h.Gather(&acc)
+	require.NoError(t, h.Init())
-	require.NoError(t, err)
+	require.NoError(t, h.Gather(&acc))
 
 	expectedFields := map[string]interface{}{
 		"http_response_code": http.StatusOK,
@@ -673,9 +674,10 @@ func TestMethod(t *testing.T) {
 		},
 		FollowRedirects: true,
 	}
+
 	acc = testutil.Accumulator{}
-	err = h.Gather(&acc)
+	require.NoError(t, h.Init())
-	require.NoError(t, err)
+	require.NoError(t, h.Gather(&acc))
 
 	expectedFields = map[string]interface{}{
 		"http_response_code": http.StatusMethodNotAllowed,
@@ -705,9 +707,10 @@ func TestMethod(t *testing.T) {
 		},
 		FollowRedirects: true,
 	}
+
 	acc = testutil.Accumulator{}
-	err = h.Gather(&acc)
+	require.NoError(t, h.Init())
-	require.NoError(t, err)
+	require.NoError(t, h.Gather(&acc))
 
 	expectedFields = map[string]interface{}{
 		"http_response_code": http.StatusMethodNotAllowed,
@@ -742,9 +745,10 @@ func TestBody(t *testing.T) {
 		},
 		FollowRedirects: true,
 	}
+
 	var acc testutil.Accumulator
-	err := h.Gather(&acc)
+	require.NoError(t, h.Init())
-	require.NoError(t, err)
+	require.NoError(t, h.Gather(&acc))
 
 	expectedFields := map[string]interface{}{
 		"http_response_code": http.StatusOK,
@@ -772,9 +776,10 @@ func TestBody(t *testing.T) {
 		},
 		FollowRedirects: true,
 	}
+
 	acc = testutil.Accumulator{}
-	err = h.Gather(&acc)
+	require.NoError(t, h.Init())
-	require.NoError(t, err)
+	require.NoError(t, h.Gather(&acc))
 
 	expectedFields = map[string]interface{}{
 		"http_response_code": http.StatusBadRequest,
@@ -808,9 +813,10 @@ func TestStringMatch(t *testing.T) {
 		},
 		FollowRedirects: true,
 	}
+
 	var acc testutil.Accumulator
-	err := h.Gather(&acc)
+	require.NoError(t, h.Init())
-	require.NoError(t, err)
+	require.NoError(t, h.Gather(&acc))
 
 	expectedFields := map[string]interface{}{
 		"http_response_code":    http.StatusOK,
@@ -846,9 +852,10 @@ func TestStringMatchJson(t *testing.T) {
 		},
 		FollowRedirects: true,
 	}
+
 	var acc testutil.Accumulator
-	err := h.Gather(&acc)
+	require.NoError(t, h.Init())
-	require.NoError(t, err)
+	require.NoError(t, h.Gather(&acc))
 
 	expectedFields := map[string]interface{}{
 		"http_response_code":    http.StatusOK,
@@ -886,8 +893,8 @@ func TestStringMatchFail(t *testing.T) {
 	}
 
 	var acc testutil.Accumulator
-	err := h.Gather(&acc)
+	require.NoError(t, h.Init())
-	require.NoError(t, err)
+	require.NoError(t, h.Gather(&acc))
 
 	expectedFields := map[string]interface{}{
 		"http_response_code":    http.StatusOK,
@@ -926,9 +933,10 @@ func TestTimeout(t *testing.T) {
 		},
 		FollowRedirects: true,
 	}
+
 	var acc testutil.Accumulator
-	err := h.Gather(&acc)
+	require.NoError(t, h.Init())
-	require.NoError(t, err)
+	require.NoError(t, h.Gather(&acc))
 
 	expectedFields := map[string]interface{}{
 		"result_type": "timeout",
@@ -962,13 +970,7 @@ func TestBadRegex(t *testing.T) {
 		FollowRedirects: true,
 	}
 
-	var acc testutil.Accumulator
+	require.ErrorContains(t, h.Init(), "failed to compile regular expression")
-	err := h.Gather(&acc)
-	require.Error(t, err)
-
-	absentFields := []string{"http_response_code", "response_time", "content_length", "response_string_match", "result_type", "result_code"}
-	absentTags := []string{"status_code", "result", "server", "method"}
-	checkOutput(t, &acc, nil, nil, absentFields, absentTags)
 }
 
 type fakeClient struct {
@@ -981,6 +983,10 @@ func (f *fakeClient) Do(_ *http.Request) (*http.Response, error) {
 }
 
 func TestNetworkErrors(t *testing.T) {
+	cl := client{
+		httpClient: &fakeClient{err: &url.Error{Err: &net.OpError{Err: &net.DNSError{Err: "DNS error"}}}},
+		address:    "",
+	}
 	// DNS error
 	h := &HTTPResponse{
 		Log:             testutil.Logger{},
@@ -989,12 +995,12 @@ func TestNetworkErrors(t *testing.T) {
 		Method:          "GET",
 		ResponseTimeout: config.Duration(time.Second * 20),
 		FollowRedirects: false,
-		client:          &fakeClient{err: &url.Error{Err: &net.OpError{Err: &net.DNSError{Err: "DNS error"}}}},
+		clients:         []client{cl},
 	}
 
 	var acc testutil.Accumulator
-	err := h.Gather(&acc)
+	require.NoError(t, h.Init())
-	require.NoError(t, err)
+	require.NoError(t, h.Gather(&acc))
 
 	expectedFields := map[string]interface{}{
 		"result_type": "dns_error",
@@ -1020,8 +1026,8 @@ func TestNetworkErrors(t *testing.T) {
 	}
 
 	acc = testutil.Accumulator{}
-	err = h.Gather(&acc)
+	require.NoError(t, h.Init())
-	require.NoError(t, err)
+	require.NoError(t, h.Gather(&acc))
 
 	expectedFields = map[string]interface{}{
 		"result_type": "connection_failed",
@@ -1053,9 +1059,10 @@ func TestContentLength(t *testing.T) {
 		},
 		FollowRedirects: true,
 	}
+
 	var acc testutil.Accumulator
-	err := h.Gather(&acc)
+	require.NoError(t, h.Init())
-	require.NoError(t, err)
+	require.NoError(t, h.Gather(&acc))
 
 	expectedFields := map[string]interface{}{
 		"http_response_code": http.StatusOK,
@@ -1084,9 +1091,10 @@ func TestContentLength(t *testing.T) {
 		},
 		FollowRedirects: true,
 	}
+
 	acc = testutil.Accumulator{}
-	err = h.Gather(&acc)
+	require.NoError(t, h.Init())
-	require.NoError(t, err)
+	require.NoError(t, h.Gather(&acc))
 
 	expectedFields = map[string]interface{}{
 		"http_response_code": http.StatusOK,
@@ -1116,14 +1124,14 @@ func TestRedirect(t *testing.T) {
 		require.NoError(t, err)
 	})
 
-	plugin := &HTTPResponse{
+	h := &HTTPResponse{
 		URLs:                []string{ts.URL},
 		ResponseStringMatch: "test",
 	}
 
 	var acc testutil.Accumulator
-	err := plugin.Gather(&acc)
+	require.NoError(t, h.Init())
-	require.NoError(t, err)
+	require.NoError(t, h.Gather(&acc))
 
 	expected := []telegraf.Metric{
 		testutil.MustMetric(
@@ -1175,8 +1183,8 @@ func TestBasicAuth(t *testing.T) {
 	}
 
 	var acc testutil.Accumulator
-	err := h.Gather(&acc)
+	require.NoError(t, h.Init())
-	require.NoError(t, err)
+	require.NoError(t, h.Gather(&acc))
 
 	expectedFields := map[string]interface{}{
 		"http_response_code": http.StatusOK,
@@ -1208,8 +1216,8 @@ func TestStatusCodeMatchFail(t *testing.T) {
 	}
 
 	var acc testutil.Accumulator
-	err := h.Gather(&acc)
+	require.NoError(t, h.Init())
-	require.NoError(t, err)
+	require.NoError(t, h.Gather(&acc))
 
 	expectedFields := map[string]interface{}{
 		"http_response_code":         http.StatusNoContent,
@@ -1241,8 +1249,8 @@ func TestStatusCodeMatch(t *testing.T) {
 	}
 
 	var acc testutil.Accumulator
-	err := h.Gather(&acc)
+	require.NoError(t, h.Init())
-	require.NoError(t, err)
+	require.NoError(t, h.Gather(&acc))
 
 	expectedFields := map[string]interface{}{
 		"http_response_code":         http.StatusNoContent,
@@ -1275,8 +1283,8 @@ func TestStatusCodeAndStringMatch(t *testing.T) {
 	}
 
 	var acc testutil.Accumulator
-	err := h.Gather(&acc)
+	require.NoError(t, h.Init())
-	require.NoError(t, err)
+	require.NoError(t, h.Gather(&acc))
 
 	expectedFields := map[string]interface{}{
 		"http_response_code":         http.StatusOK,
@@ -1310,8 +1318,8 @@ func TestStatusCodeAndStringMatchFail(t *testing.T) {
 	}
 
 	var acc testutil.Accumulator
-	err := h.Gather(&acc)
+	require.NoError(t, h.Init())
-	require.NoError(t, err)
+	require.NoError(t, h.Gather(&acc))
 
 	expectedFields := map[string]interface{}{
 		"http_response_code":         http.StatusNoContent,
@@ -1348,9 +1356,11 @@ func TestSNI(t *testing.T) {
 			ServerName:         "super-special-hostname.example.com",
 		},
 	}
+
 	var acc testutil.Accumulator
-	err := h.Gather(&acc)
+	require.NoError(t, h.Init())
-	require.NoError(t, err)
+	require.NoError(t, h.Gather(&acc))
+
 	expectedFields := map[string]interface{}{
 		"http_response_code": http.StatusOK,
 		"result_type":        "success",
@@ -1367,3 +1377,90 @@ func TestSNI(t *testing.T) {
 	absentFields := []string{"response_string_match"}
 	checkOutput(t, &acc, expectedFields, expectedTags, absentFields, nil)
 }
+
+func Test_isURLInIPv6(t *testing.T) {
+	tests := []struct {
+		address url.URL
+		want    bool
+	}{
+		{
+			address: parseURL(t, "http://[2001:db8:a0b:12f0::1]/index.html"),
+			want:    true,
+		}, {
+			address: parseURL(t, "http://[2001:db8:a0b:12f0::1]:80/index.html"),
+			want:    true,
+		}, {
+			address: parseURL(t, "https://[2001:db8:a0b:12f0::1%25eth0]:15000/"), // `%25` escapes `%`
+			want:    true,
+		}, {
+			address: parseURL(t, "https://2001:0db8:0001:0000:0000:0ab9:C0A8:0102"),
+			want:    true,
+		}, {
+			address: parseURL(t, "http://[2607:f8b0:4005:802::1007]/"),
+			want:    true,
+		}, {
+			address: parseURL(t, "https://127.0.0.1"),
+			want:    false,
+		}, {
+			address: parseURL(t, "https://google.com"),
+			want:    false,
+		}, {
+			address: parseURL(t, "https://thispagemayexist.ornot/index.html"),
+			want:    false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.address.String(), func(t *testing.T) {
+			if got, _ := isURLInIPv6(tt.address); got != tt.want {
+				t.Errorf("isURLInIPv6() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func Test_isIPNetInIPv6(t *testing.T) {
+	tests := []struct {
+		address *net.IPNet
+		want    bool
+	}{
+		{
+			address: &net.IPNet{
+				IP:   net.IPv4(127, 0, 0, 1),
+				Mask: net.CIDRMask(8, 32),
+			},
+			want: false,
+		}, {
+			address: &net.IPNet{
+				IP:   net.IP{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1},
+				Mask: net.CIDRMask(128, 128),
+			},
+			want: true,
+		}, {
+			address: &net.IPNet{
+				IP:   net.IPv4(192, 168, 0, 1),
+				Mask: net.CIDRMask(24, 32),
+			},
+			want: false,
+		}, {
+			address: &net.IPNet{
+				IP:   net.ParseIP("fe80::43ac:7835:471a:faba"),
+				Mask: net.CIDRMask(64, 128),
+			},
+			want: true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.address.String(), func(t *testing.T) {
+			if got := isIPNetInIPv6(tt.address); got != tt.want {
+				t.Errorf("isIPNetInIPv6() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func parseURL(t *testing.T, address string) url.URL {
+	u, err := url.Parse(address)
+	require.NoError(t, err)
+	require.NotNil(t, u)
+	return *u
+}